Effect of two chemosterilants apholate and hempa on the bone-marrow chromosomes of mice.

Abstract

Mice were injected with 0.1% solution of apholate and hempa at the rate of 1.5 ml per 100 gm body weight and their bone-marrow cells were fixed at different intervals between 15 min and 144 hr. Specimens injected with distilled water served as controls.Only three aberrations were found in 4,100 metaphases in the control series. In the hempa-treated series, out of 4,100 metaphases examined one chromatid break, one subchromatid break, two gaps and one exchange were found at 24 hr only.In the apholate-treated series aberrations were absent only at 15 min and 144 hr post injection. At other times the aberrations were single chromatid breaks, subchromatid breaks, aniso- and isochromatid breaks, constrictions, gaps and lesions and exchanges. The aberration peak of 28.2% was reached at 24 hr, and fell to 0.3% at 120 hr. The breaks were non-randomly distributed between and within chromosome groups. Groups I and II and distal region of all affected groups were most susceptible.The mode of action of apholate and hempa in the induction of chromatid aberrations in mice, their localization and non-random distribution are discussed. The role of the aziridine groups in inducing aberrations has been considered. It is suggested that the breaks were due to some direct action and that the chromatids of mice contain some weaker regions.